mm_flynn

The thread on the accident at Southend has prompted some questions in my mind.

As I understand it,

1 - Everything took place OCAS.
2 - The C-150 was classified as a training flight (Z) - which makes sense
3 - The Meridian was classified as a Normal flight under IFR

Now some assumptions of mine

1 - A Normal IFR flight when leaving controlled airspace will be treated as having asked for a RAS when handed over for ATCOCAS.

2 - The Normal IFR flight (be it a 747 or a c150) will be given priority over Z flights.

Now my questions

A - Is it possible to be Normal and VFR?

B - It appear that an IFR FP which doesn't enter UK class A airspace doesn't count as 'filed in the normal way' as these flight plans seem to be treated like a VFR flight plan. Is this true?

C - Air filing a FP (as in getting a Class D IFR clearance) doesn't appear to count as 'filed in the normal way' so you are still Z in this situation, True?

D - Is the only way to be a Normal flight to be flying on a CFMU validated IFR flight plan (that enters Class A in the UK)?

E - Does ATC ask what service the IFR is looking for, particularly in the situation that faced the Southend controllers (i.e. where they are going to struggle to make the plan work on the basis of providing RAS but might have been able to under a RIS for the Meridian?

Chilli Monster

Assumption first

If the unit has a policy of IFR inbounds always being RAS, then yes. However, if no policy is in place then the aircrat should be asked what service it requires on leaving CAS (unless you feel the question will be too difficult / not understood!)

Questions

A) Yes

B) No - IFR is IFR, whether inside or outside CAS for the purposes of being handled by ATC. Flight Plan handling is a different matter entirely, but makes no difference in the priority scheme of things

C) False, but it only counts for that airspace. However, bear in mind the main purpose of that class 'D' is to facilitate arrivals and departures from that airport. So, some 'normal' flights get afforded more 'priority' over others

D) No - see answers above

E) See answer to assumption above

mm_flynn

Thank you CM. Answers which are different from my expectations (as you can probably tell by the way the questions are phrased ).

My experience seems that if I am just flying around (even if on a VFR FP - for say an international flight) getting crossings and radar service I am treated as Z. However, if I am on what I would call an airways flight plan ATC parts the seas for me when OCAS or transiting in and out of controlled airspace. (thank you all for the great job you do)

Other than the obvious case of a local training flight, how does ATC determine if a flight is Normal or Z - as my theory is clearly incomplete at best.

cdb

Well, experience!

If someone calls up as say, Atlantic 43 in a cessna 152, then its a pretty sure bet! On the other hand, we know that Atlantic 401 in a C401 is probably not.

Other operators use a S (for solo) or T (for training) suffix eg speedbird 24 Tango.

In addition, you can get a good idea from the confidence and fluency on the RT.

Finally, the pilot will often tell you. If you're on a QXC, or a photo survey tell us.

landedoutagain

Although, somewhat ironically, Atlantic 401 is pretty much always a C404 (in my experience), and could be a cat Z flight, or at least treated as such. Could be a cat B flight too, but thats quite rare...

mm_flynn

The question was around the general comment I see in many of the threads along the lines of 'The VFR can orbit while we get the commercial in" - now as far as I can see in all of the reference's people have posted their is nothing that says IFR has priority over VFR or AOC operator has priority over non-AOC operator (or even based AOC operator has priority over non-based ). The priority listing is pretty much 'emergency', 'specific government ops', Normal, everyone else. And within a category it is basically first come first served.

Being Z, like the poor chap at Southend means you have every possibility of orbiting, being broken off on final, waiting at an intersection while a bunch of other people go ahead.

I don't want to believe that you get classed as Z based on how slick your machine is and how good your RT is. You guys must employee the bouncers from Club 414 to make the calls !! And in the same context coming out of the airways seems to have the same cachee as stepping out of Roman Abramovich's limo.

Chilli Monster

That, believe it or not, has nothing to do with the flight priority system. It's a judgement call - what is the most efficient way of dealing with the conflict?

Part of the job of ATC is expedition. Now - what saves more time overall? A C152 (for example) orbiting for 2 minutes, or a B737 going around back into the radar pattern for 10 minutes? It's a no-brainer!

By the same concept if I've got 2 or 3 light aircraft departures I can get away before a medium departure, from an intersection, I do it. Why? The commercial gets delayed for 1 minute rather than the lights getting delayed for 3-4. If I've got a light in the circuit and the medium at 9-10 miles I'll tell him to keep it tight to be no.1. Reason - it cuts down the overall delay.

And therein lies your answer. ATC is, purely and simply, a numbers game. An hour is a finite period of time - 60 minutes. How do I maximise the number of movements achieved in that finite period of time SAFELY? Once you grasp that concept, the whole situation starts to make sense.

mm_flynn

I understand the expedition point and agree totally that the sequence might not be strict first come first serve.

It must just be some recent bad luck on my part. For example, I am lined up at an intersection (VFR and reasonable VMC) checks ready to go on an intersection departure and a 767 pushes but is still waiting for his airways clearance. I sit, watch him go past, backtrack down the runway, line up, sit and wait for his clearance and go - about 8 minutes. Of course now I need to wait, then backtrack because of his wake. I am obviously not an ATCO (you can tell by the dim questions ) but this seems like a priority call not an efficiency call. Hence my assumption of being Z (note my machine climbs out at around 110 knots the airport was class G )

Spitoon

Chilli describes the real world well. I doubt that many controllers actively think 'what category is this flight' on first contact or whenever a decision has to be made on who goes first. The category table is something learnt for an exam in college and then forms the basis (but only the basis) for the huge number of variable that are considered when a controller decides on the order of traffic etc.

As an aside, whilst I sympathise with what seems like, and might well have been, an unnecessary delayI'm trying to think which airport it might be that is in Class G and has 767 operations. The only words of consolation I could add is that a controller that is at an airport that is in Class G may have a lot of co-ordination to do with the area controllers in order to get the 767 airborne.

10W

It's my experience as well that on the ball ATCOs (which are the vast majority) will do the best for the overall traffic flow at any given airfield.

Some need a nudge occasionally (advising you are ready immediate or can take an early turn after departure for example), and a small number are ultra safe and over cautious.

I was cleared ahead of this one even though I got to the intermediate holding point whilst he was lined up .... with an acceptance of an early turn out to help smooth things along.

Eric T Cartman

10W
You should expect nothing less from Scotland's number 1 low cost airport !!

chevvron

Bear in mind that An124/225 need up to 10 minutes lined up to spool up to takeoff thrust; that's probably what he was doing!